A little variety and chaos in the garden is good for our minds. It keeps us from getting into the same old rut of "this plant here and that plant there."
So, if you are like me, you like to have self-seeding plants in the garden to change the scenery ever year. A "self-seeding plant" generally refers to biennials, short-lived perennials and some hardy annuals that live for a short time, set seed sending their abundance into the garden, and then go dormant or die altogether.
If you are someone who likes absolute order in the garden, then self-seeders are not for you. However, if you like some randomness or unpredictability, then self-seeding plants are just perfect.
I am not talking about weedy plants like purple loosestrife that self-seed and take over, becoming a nuisance. No, not those beasts.
I am referring to charming plants of merit that add character and charm to the garden that can be controlled with little effort to grow in the locations you or they choose.
One of the great advantages of self-seeders beyond their unpredictability is that they are free once you purchase the initial plant and allow it to go to seed. Self-seeding plants provide an abundance of seed that can be stored in the refrigerator for future use or the seed can be harvested when ready to be directly sown into the garden where you want the plant to grow the following year.
To harvest seed from self-seeders you have to allow the flower stalk to stand in the garden and grow the seeds to maturity, so some tolerance of their browning seed stalks is required to achieve success. Seeds can be spread naturally by wind, by falling to the ground, sometimes by small animals or rainfall or as occurs in my garden by my leaf blower which blows them all over the place.
Most of the self-seeders produce heavy seeds that re-seed close to where the mother plant grew. If you want them to grow somewhere else you have to collect and scatter the seeds where you would like them to grow the next season. If you mulch your garden beds, then you have to collect the seeds, store them in the refrigerator and scatter the seeds into the garden in February so they can germinate in time for summer bloom.
The most common example of such plants would be foxglove (Digitalis species), which produces tall stalks with tubular flowers in pink, purple or white shades in summer. Since foxgloves are biennial, they grow leaves and roots in the first year of their life and produce flowers in the second year, then they set seed and die. The great advantage of foxgloves and many other self-seeding plants is that they move around the garden and flower from year to year in new locations, adding a wild card design component to the garden. You'll never quite know where they will appear.
Another common self-seeding plant called mullein (Verbascum species) is native to Europe and Asia but is widely naturalized in British Columbia. It is a biennial or shortlived perennial that forms a rosette of fuzzy grey-green leaves at ground level in Year 1 and in Year 2 sends up a tall flowering spike one metre tall with usually yellow flowers, but different species produce shades of orange, red-brown, purple or white flowers.
One of my favourite self-seeders is the California poppy (Eschscholzia californica) which has blue-green, lacey foliage that grows 15-30 cm tall with silky soft flowers in shades or yellow, orange, red and white. Eschscholzia grows best in sunny, dry open locations with poor to average soil. Once the California poppy sets seed, the mother plant will die during our cold winter climate but the seeds are usually hardy enough to survive until the next year or harvest seeds and store in the refrigerator for use the following year.
There are also short-lived and long-lived perennial plants that produce large amounts of seed. The best example of a desirable self-seeding perennial would be the Welsh poppy (Mecanopsis cambrica). This plant is not for everyone because it can self-seed prolifically and become a nuisance. However, this poppy grows in part shade or full sun, needs no water or fertilizer and it's not fussy about soil type as long the soil is not waterlogged. The plants grow about 40 cm tall and flower from early spring until mid-summer with a bright, cheerful yellow flower that's frilly and charming, and the seed heads add interesting structural elements in the garden.
Remember that nature abhors a monoculture and too much uniformity. So try to free your mind from conformity and allow some self-seeding plants to add a bit of unpredictability to the garden.
Todd Major is a journeyman horticulturist, garden designer, consultant and organic advocate. For advice contact him at stmajor@ shaw.ca.